Transcript Evolution in Action

Evolution in Action
Chapter 15 Section 3
Convergent Evolution

Different species become more similar.
– Example #1: Birds and bats
– Example #2: Dolphins and sharks
Divergent Evolution (Adaptive Radiation)

Similar species become more different.
– Example: The kit fox and red fox
– Example: Lions and tigers
– Example: Turtles and tortoises
Convergent or Divergent Evolution?
Divergent
Closely related species evolve in different
directions
Convergent or Divergent Evolution?
Convergent
Unrelated species evolve similar
characteristics
Convergent or Divergent Evolution?
Divergent
Closely related species evolve in different
directions
Convergent or Divergent Evolution?
Convergent
Unrelated species evolve similar
characteristics
Artificial Selection
Humans select individuals with the traits they
want
 Then breed them to produce more individuals
with those traits
 Speeds up the process of divergent evolution

Coevolution
 When
two species influence
each other’s evolution
– Example: Snails & Crabs
– Example: Plants & their pollinators
– Example: Shells of murex snails
evolved to become thicker and
spinier. In response, crabs that eat
snails evolved more powerful claws
strong enough to crack the snails’
shells.
Coevolution
 Video